| 摘要 |
According to one embodiment, a semiconductor device having a semiconductor substrate, first to fourth semiconductor layers of nitride, first to third electrodes and a gate electrode is provided. The first semiconductor layer is provided directly on the semiconductor substrate or on the same via a buffer layer. The second semiconductor layer is provided so as to be spaced apart from the first semiconductor layer. The third semiconductor layer is provided on the second semiconductor layer and has a band gap wider than that of the second semiconductor layer. The fourth semiconductor layer insulates the first and second semiconductor layers. The first electrode forms an ohmic junction with the first to the third semiconductor layers. The second electrode is provided on the third semiconductor layer. The gate electrode is provided between the first and the second electrodes. The third electrode forms a Schottky junction with the first semiconductor layer. |
